Mammography, including x-ray imaging and other imaging modalities, is widely used in detection and analysis of cysts, lesions, microcalcifications and other areas of interest within a patient's breast. Because of its proved effectiveness in early detection and analysis, including detection of nonpalpable lesions, mammography continues to be recommended for many women. As a result, mammography equipment is available in many locations and such equipment, as well as clinicians and physicians experienced in using such equipment and analyzing the mammographic images, are typically kept busy meeting the demand.
Traditionally, mammography systems have been film-based. Film based mammography involves obtaining mammographic images on film which is typically loaded into a film tray positioned adjacent the patient's breast. The films can then be reviewed using a light box. More recently, digital mammography has been gaining acceptance. In digital mammography, images are acquired digitally and can be displayed on an electronic monitor.
A number of advantages associated with digital imaging have been recognized. First, digital imaging provides substantially real-time images. In some cases, follow-up views may be acquired based on real-time review of the digital images such that a return visit by the patient can be avoided. In addition, digital processing allows for image enhancement. In this regard, a physician may zoom in on an area of interest, adjust the image contrast or brightness or otherwise manipulate the image after acquisition. Moreover, it is sometimes possible to obtain improved diagnostic information by digital processing. For example, a digital image that is identified as being suspicious or is otherwise of interest can be exported to certain CAD systems that perform digital analyses. For example, such CAD systems may perform a pixel-by-pixel analysis of the digital image to identify areas of reduced intensity that may be missed upon review of the images using the naked eye. Such areas may indicate microcalcifications or other conditions of interest that the physician may desire to review more closely, such as by zooming in on that region of the image or otherwise enhancing the image.
Despite these advantages, certain perceived disadvantages have slowed the process of full digital acceptance. Some of the perceived disadvantages are specific to particular digital imaging equipment. In this regard, some current digital imaging systems do not provide a full field of view for a patient's breast. As a result, multiple images may be required for a screening analysis or the digital imaging system may be relegated to follow-up imaging of an area identified by film. In addition, some current digital imaging systems provide a limited resolution that may be deemed insufficient for certain applications. However, full field, high-resolution digital imaging systems are now being marketed, including the SenoScan system of Fischer Imaging Corp. of Thornton, Colo.
Other perceived disadvantages relate to operational restrictions of conventional digital mammography systems. Many conventional digital mammography systems are stand alone units that include the image acquisition equipment or gantry (e.g., the x-ray tube, compression paddles, detector and the like), a processor executing image processing logic and a display terminal that may include oversized high resolution monitors. In these cases, a physician may review images at the physical equipment site. This may tie up the equipment when needed, thereby reducing patient throughput or require that the physician plan around a schedule for accessing the equipment.
Moreover, the images available for review at the equipment may be limited. In this regard, physicians may desire to compare current images for a patient to images obtained for that patient at an earlier date, perhaps obtained using different equipment. Physicians may otherwise desire to review images obtained for multiple patients at different image acquisition sites, e.g., in connection with a large medical facility. In such cases, the images desired for a particular review session may not be readily available at the equipment site. Additionally, certain tools such as CAD processing or other diagnostic tools may not be available at each site where patient images reside.